Cities have made great strides in reducing murders of young men. The next step will be much harder.

Peters won the nickname on the basketball court, where he had a dangerous left hand and a swagger reminiscent of another “Truth,” Celtics star Paul Pierce. But to those who knew him best, the name resonated beyond basketball. He was the little brother who was convinced he was the oldest, the natural musician who could play any instrument that was put in his hands, the generous child who invited friends over for dinner when they didn’t have enough at home.

A newspaper clipping of the obituary for Damond Peters.

“He was also the truth in life,” said Patrina Peters, his mother.

But Damond was a young black man in New Orleans, a city where more than 100 black men are gunned down each year and hundreds more see their lives derailed by jail or prison. And so Patrina Peters worried. She worried more after Hurricane Katrina, which shuttered the strict Christian school that had been a source of stability for Damond and left him moving from school to school. She worried even more after he was arrested on drug charges at age 18, and more still when he was arrested in connection with a murder, though the district attorney didn’t pursue charges.

So even though Damond was an adult, Patrina Peters set a strict curfew and held him to it. By evening, “if he hasn’t called me, I’m blowing his phone up,” she recalled. When Damond’s number showed up on her phone shortly before 8 p.m. on May 26, 2010, she wasn’t surprised — until she picked up and the voice on the other end of the line wasn’t his.

“Miss Peters?” the voice said. “Do you know who this phone belongs to?”

The voice belonged to a detective. Police had found the phone next to a body. Did she have a son? Yes. Was he tall? Yes, 6-foot-1. Did he have any tattoos? Yes — she’d “brought hell down on him” when he came home with the first one. Could she describe them?

The body was Damond’s. He was 19 years old.

“It broke me,” Peters said. “After all of the fighting and all of the struggling and thinking I made the right decisions, to be a woman who lost her son to these streets … I still felt I failed. I still thought, ‘What else? What else could I have done?’”

Patrina Peters, whose son, Damond, was killed in 2010, keeps a photo album of him in her New Orleans home.

New Orleans is asking the same question: What can the city do to save lives like Damond Peters’s? Damond was the 87th person murdered in New Orleans in 2010; 88 more would follow by the end of the year, according to the New Orleans Police Department. Most were young black men.

Mayor Mitch Landrieu, who took office three weeks before Damond’s death, has made reducing murder one of the centerpieces of his administration in a way that few New Orleans mayors — or big-city mayors, period — have done. In 2012, he launched “NOLA for Life,” an ambitious effort to reduce murder through a combination of data-driven policing, aggressive prosecution and a variety of programs aimed at treating the deeper problems underlying the violence: midnight basketball, summer jobs, mentoring, neighborhood restoration efforts.1

The problem that Landrieu is tackling is one that has plagued New Orleans for well over a century. Visiting the city in 1861, British journalist William Howard Russell spoke to the local sheriff, who told Russell that the city was “a perfect hell upon earth” because of its high rate of violent crime and the tendency of its residents to carry firearms. Violence has ebbed and flowed in the decades since, and murders fell steeply in the late 1990s, as they did in much of the country. But New Orleans’s murder rate has been well above the national rate for decades, and in many years, the city has held the dubious title of the country’s “murder capital.” In April, the killing of former New Orleans Saints player Will Smith — who was shot after a car crash — drew national headlines.

Low-profile murders like Damond Peters’s are far more common. Nationally, more than 6,000 young men ages 15 to 34 are killed in gun homicides each year2; two-thirds of them are black. The murder rate among young men has fallen much more slowly than violent crime overall. The figures in New Orleans are even starker: According to the New Orleans Police Department, nearly 80 percent of murder victims in 2015 were black men, most of them younger than 35.3

Most murders in New Orleans fall under what is often called street violence, a term that encompasses gang violence and drug-related killings but also a much wider universe of fights and arguments. Landrieu has worked to bring equal attention to these deaths, which he called the “shame of our city” in a speech at Tulane University shortly after Smith’s murder.

“The deadly violence is with us every day, all day,” Landrieu said. “And the media goes through the motions, which frames our thinking and discussion. A murder or shooting or armed robbery means 90 seconds at the top of the hour. … But that’s it. No broader context. No further discussion about what has become the wallpaper of American life — always in the background, but little noticed.”

Nearly all of New Orleans’s murders — 92 percent in 2014, according to FBI data — are committed with guns. Yet none of NOLA for Life’s long list of programs explicitly aims to reduce the number of guns on the city’s streets. This spring, Landrieu proposed a series of gun regulations, including banning guns from parks and prohibiting owning or selling guns without a serial number. But several of the proposals merely codify existing state law, and even some backers don’t claim they will make much difference.

Landrieu’s caution is less about ideology than political reality. Louisiana has one of the highest rates of gun ownership in the country, and the Republican-controlled state legislature is highly resistant to any effort to limit gun ownership. “Louisiana is a sportsman’s state,” said Michael Harrison, the city’s chief of police. “The people love their guns.”

NOLA for Life scored some early successes. There were 150 murders in New Orleans in 2014, the fewest in more than 40 years.4 Since then, however, progress has slowed. Landrieu’s critics suggest that the effort is losing steam; the administration defends its record but acknowledges that after early progress, further gains have become more difficult.

But beneath the local political wrangling, there is a larger lesson in New Orleans’s murder reduction effort. In recent decades, cities across the country have learned how to combat gun violence through innovative law enforcement strategies. But they have made far less progress in addressing the underlying problems that lead to that violence — and in focusing those efforts on the people who need them most.

Peters has many pictures of Damond on her phone.

Damond Peters’s death was senseless, but it wasn’t random. Although his murder, like roughly half of those in New Orleans and a third of killings nationally, remains unsolved, it’s clear that he was targeted: He was shot multiple times and left by the side of the road. And, looking back, there were warning signs that he could become a victim of violence: the drugs, the arrests. The success of NOLA for Life — both its law enforcement and prevention strategies — hinges on identifying those warning signs while there is still time to intervene.

Gun violence has long been referred to as an “epidemic,” but researchers are increasingly taking that term literally and treating violence as a public health problem. The approach requires a shift in mindset, a focus not on catching bad guys but on stopping the spread of a disease.

One key question when trying to stop the spread of any disease is how does it pass from person to person. Popular narratives around gun violence often make it sound like a highly contagious disease similar to the flu: People grow up surrounded by a “culture of violence” and are infected by it. But research has shown that violence more closely resembles a different model: HIV. People aren’t infected by the “disease” of violence just by growing up in a high-crime neighborhood or even by witnessing violent incidents. Rather, the spread requires person-to-person contact — being the victim of violence, for example, or being drawn into a gang in which violence is not just accepted but actively taught — which creates a network of violence.

“If you don’t know the people in the network and you’re not hanging out with them and you’re not engaging in exchanges with them, then you’re probably not at very high risk,” said Tracey Meares, a Yale professor who has studied gun violence.

Some of the most important work on the spread of violence comes from Meares’s Yale colleague Andrew Papachristos, a sociologist who began studying the issue as a graduate student in Chicago in 2001. At the time, researchers were looking mostly for risk factors that predicted criminal activity such as poverty, low levels of education or an unstable family life. The problem was that such factors applied to a majority of residents in huge swaths of Chicago’s low-income neighborhoods, yet relatively few people ever shot anyone.

Papachristos instead looked at the structure of violence — how were incidents, and the people involved in them, connected? He found that a small group of people, nearly all already known to law enforcement, was responsible for an outsize share of shootings. By starting with the victim and tracing his connections through police records, he was able to describe for the first time the networks of violence in Chicago and later other cities.

The numbers are breathtaking. In Chicago, the overall rate of non-fatal shootings was about 62 per 100,000 people.5 But in the networks that Papachristos identified, rates were about 12 times as high. In city after city that Papachristos has examined, 3 percent to 7 percent of the population is responsible for 50 percent to 60 percent of the shootings.

Papachristos’s work relies on a key insight that experts have long known but was rarely discussed publicly: The victims and perpetrators of violence are largely the same people. Reducing gun violence, then, requires focusing on exactly the murders that rarely get attention — murders like Damond Peters’s.

“If you want to shift the discussion about gun violence and if you want a lower homicide rate, that means you need to save the lives of the people getting shot,” Papachristos said. “If you want to drive the rate down, you’ve got to save the lives of young men with felony convictions.”

Darren Alridge now works at the New Orleans nonprofit organization where he took GED classes. Alridge calls on counselors at the Youth Empowerment Project to recognize outstanding students in their charge.

Darren Alridge was born six months after Damond Peters and like Peters grew up in the Lower 9th Ward. He, too, had a mother determined to give her children a better life: “She was a strict mom,” Alridge recalled, “but she was strict for a reason.” His life, too, was upended by Katrina; he bounced from city to city and school to school before dropping out in his junior year of high school. And he, too, got in trouble with the law. He started dealing drugs and in 2009 was arrested at age 18 and charged with illegally carrying a gun and possession of a stolen car.

But there the two men’s stories diverge. A judge gave Alridge a choice: Spend two years behind bars or earn a GED. Alridge chose the GED.

Still, he was skeptical. He had struggled in school, especially after Katrina, and started getting into fights. But the Youth Empowerment Project, the New Orleans nonprofit organization where Alridge went for his GED, was different. “As soon as I walked in the door, it was home,” he said.

Seven years later, Alridge is still at YEP, now as a full-time staff member overseeing recreation activities in the after-school and summer programs for children as young as 5. It’s a 24/7 job — it isn’t unusual for him to get a call at 7 p.m. from a student saying, “Mr. D, I need a school shirt for tomorrow” — but Alridge is proud of his status as a role model. When he walks into the former bank that serves as YEP’s youth center, he is quickly surrounded by children eager to tell him about their days.

“This is about the happiest I’ve ever been,” Alridge said. “Not a lot of the people I grew up with are out here doing something positive.”

Alridge is in some sense a law-enforcement success story. He was arrested before he could commit a more serious offense; he was presented with serious consequences, given the chance to take a different path and provided with the tools necessary to succeed.

Alridge leads students in playground games, including a competition to see who can hula-hoop the longest.

But stories like his are all too rare in New Orleans, which has one of the highest incarceration rates in the nation and a police force with a history of corruption and abuse. Since 2012, the police department has been operating under federal oversight because of what the Department of Justice called “serious, systemic, wide-ranging, and deeply rooted” problems, including the excessive use of force, unconstitutional detentions and racial bias. That history contributes directly to street violence: Many black residents, in particular, would rather settle disputes themselves than dial 911.

Landrieu and Harrison, the police chief, have embraced the DOJ investigation and say they are working to reduce incarceration rates and rebuild trust — “strengthen the NOPD” is one of the five pillars of NOLA for Life. They point to falling numbers of complaints from residents and rising levels of satisfaction with the department as evidence that their approach is working.

Under NOLA for Life, the city focuses law-enforcement resources on the people most likely to become victims or perpetrators of gun violence: people like Darren Alridge and Damond Peters, the people in Papachristos’s networks. Using internal police data — records on arrests, firearm seizures, automobiles and real estate — they identified the people at highest risk and in October 2012 held the city’s first “call-in”: Authorities brought about three dozen men on the high-risk list into a courtroom. There, a collection of local and federal law enforcement officials — the police chief, the district attorney, the U.S. attorney — as well as the mayor, local pastors and other community leaders presented their audience with a choice not unlike the one the judge had given Alridge: Turn away from violence and we will help you find jobs, housing and other support. But if you shoot someone — or if any of your associates shoots someone — we will come after you with the full weight of the law.

The call-in strategy was first developed by David Kennedy, a criminologist credited with helping to lead Boston’s dramatic drop in crime in the 1990s. His approach predates Papachristos’s work in Chicago, but the philosophy behind it is much the same: Law enforcement should focus its efforts on the small group of people responsible for an outsize share of violent crime. For the strategy to work, there must be both a carrot and a stick: real opportunities for people who swear off violence, but also real consequences for those who don’t — no more pleading out to short sentences.

New Orleans held five call-ins in late 2012 and 2013, in combination with other strategies that have shown promise: mass indictments against suspected gang members; “hot-spot policing,” which deploys police to the areas with the most crime; and an approach pioneered in Chicago in which local community members known as “interrupters” try to mediate conflicts between rival groups.

The strategies seemed to work, at least at first. Murders fell from 200 in 2011, the year before NOLA for Life began, to 193 in 2012, to 150 in 2014. Total shootings, which many experts consider a better measure of street crime, also fell. A 2015 study by University of Cincinnati criminologists Nicholas Corsaro and Robin Engel attributed the declines to the call-ins, indictments and related strategies.

Murders rose in 2015, however, and although they are down so far in 2016, shootings are up slightly. New Orleans hasn’t yet achieved as dramatic a decline in murder as those experienced by Boston and some other cities.

Landrieu and his critics disagree over why progress has slowed. But Corsaro said that at some point, a leveling off was inevitable. The combination of call-ins and indictments succeeded in taking some of the city’s most violent offenders off the streets, or perhaps of convincing others to reform. But such strategies can only achieve so much.

“There is a diminishing return,” Corsaro said. “There has to be. If you’ve got a small percentage of gang members that are driving your violence and you focus on them and they go away for whatever reason … then you’re going to hit a ceiling.”

The offices of the Youth Empowerment Project in New Orleans, where Alridge runs after-school activities for kids.

YEP, the organization that helped Darren Alridge turn his life around, aims to do what the criminal justice system can’t, at least not on its own: provide educational, mentoring and employment opportunities to young people who might otherwise fall victim to violence. Melissa Sawyer co-founded YEP in 2004 after six of the young men she worked with at a local juvenile-justice reform organization were killed in a nine-month period.

“We were literally going to funerals every month, every other month, burying young people,” Sawyer said. “We had done a great job getting kids out of jail, but we started to ask ourselves, ‘If we are only getting young people out of jail to have them go back to communities that are as violent as they are, what are we really doing?’”

YEP now works with more than 1,000 young people ages 7 through 24 annually, offering after-school programs for elementary school students, employment readiness training for teens, and other programs. On a recent Tuesday afternoon, staff members tied paper flowers for the upcoming prom — few of the GED students had been to prom in high school — while children played basketball in a courtyard outside.

YEP doesn’t currently receive any funding through the NOLA for Life initiative, although its adult education programs do get some money from the city. But it is exactly the kind of program that the city is hoping will help stop the spread of violence before the police ever need to get involved. GED programs like the one Alridge went through offer a second chance to people who have already gotten into trouble with the law; programs targeting younger children try to head off problems before they ever start.

David Seal, who is a professor at Tulane University’s public health school and worked with the city in the early days of NOLA for Life, described concentric circles of risk: At the center is the small group of people responsible for most of the violence. One circle wider than that are, for example, teenagers who have dropped out of school but not yet fallen into violence. One circle beyond that are middle-schoolers with truancy problems, and so on. NOLA for Life, through its many programs, is meant to work at each level.

“What you really hope is you reduce the number of people at each step,” Seal said. “Let’s break the chain early.”

The trouble is that each wider circle contains exponentially more people — most of whom would never have become violent anyway. Peter Scharf, a criminologist at Louisiana State University’s School of Public Health in New Orleans, said the problem comes down to resources: The city can’t afford to provide everyone with the kind of labor-intensive resources that YEP offers. How does it decide who to help?

“You’re going to have to treat so many people to get any kind of reduction,” Scharf said.

Alridge has tattoos honoring a cousin who was fatally shot.

Alridge said he started dealing drugs to help his family — his mother worked three, sometimes four, jobs and still struggled to make ends meet. There weren’t many better options for someone without a high school diploma.

“There aren’t a lot of positive opportunities out here,” Alridge said. “If you don’t have an education, then you’re just out here on the streets.”

Landrieu, too, sees New Orleans’s murder problem as the result of deeper systemic issues: racism, inequality, poverty. Violence, Landrieu said in his April speech at Tulane, “doesn’t just come out of nowhere.”

“Murder and violence in all forms is the poisonous fruit that grows from the soil of injustice, racism and inequality — fertilized by guns, drugs, alcohol, broken families and disintegrated social structures,” Landrieu said.

He believes that by fixing the schools, creating jobs, reducing incarceration levels and rebuilding neighborhoods, the city can attack the deeper social conditions that allow the epidemic of violence to spread.

But many experts, both inside and outside New Orleans, are skeptical. The implications of Papachristos’s network analysis go beyond law enforcement: If only a tiny percentage of people are responsible for a large percentage of violence, then interventions must be similarly narrowly tailored.

“The gap [in risk] between the average citizen and the guys in my network are so exponential that you’re not going to shift it by affecting the rate of people whose risk is already zero,” Papachristos said.

Thomas Abt, a Harvard researcher who has studied gun violence, said politicians and policymakers too often think that by tackling one set of problems (poverty and inequality), they can address another (murder and violence). That, Abt said, is “fuzzy thinking.” Job training, educational opportunities and mentoring programs that target a broad population — low-income black youth, for example — are worthy efforts in their own right, but they aren’t necessarily effective at deterring violence.

“There’s little causal evidence that inequality, poverty, or that any one structural factor leads to violence,” Abt said. There is a connection between such “root causes” and violence, he said, but it isn’t direct.

Landrieu and his administration acknowledge that it’s hard to measure the impact of specific policies, especially ones like education that take years to bear fruit. But Charles West, who oversees NOLA for Life, said that although progress may have slowed, the trend line on murder still points in the right direction. “We’ve come a very long way,” West said.

Alridge, though, said he sees little change in his own community. He is attending graduations now, but also funerals. “To me, everything feels pretty much the same,” he said. “I’m still losing friends and family.”

Alridge said YEP gave him the tools to change his life. But the motivation came from somewhere else: his son, Darren Jr., who was born while Alridge was working toward his GED. “As a parent, we do all we can for our kids to have better lives,” he said. “But I just think that growing up out here and living out here and being through what I’ve been through, I just think there’s only so much you can do as a parent.”

And as the father of a young boy who will grow up to be a young black man, Alridge said he worries, just as Patrina Peters did.

Footnotes

In 2014, at Landrieu’s invitation, I spoke on a panel at a conference associated with NOLA for Life. FiveThirtyEight covered the cost of my travel, and I was not compensated for my participation.

According to 2012-14 data from the Centers for Disease Control and Prevention’s Multiple Cause of Death database.

The term “murder” in this article refers to murder and nonnegligent manslaughter, a category that excludes cases of death through negligence or justifiable homicide. The CDC’s count of homicides is broader, covering all non-accidental gun killings.

Because of Hurricane Katrina, New Orleans doesn’t have official statistics on murder or other crime for August through December of 2005. There were 168 murders through the end of July 2005.

Papachristos said he studied non-fatal shootings in Chicago because they are far more common than fatal shootings but rarely studied.

Ben Casselman is a senior editor and the chief economics writer for FiveThirtyEight. @bencasselman